FocusTraversalPolicy class abstract

Determines how focusable widgets are traversed within a FocusTraversalGroup.

The focus traversal policy is what determines which widget is "next", "previous", or in a direction from the widget associated with the currently focused FocusNode (usually a Focus widget).

One of the pre-defined subclasses may be used, or define a custom policy to create a unique focus order.

When defining your own, your subclass should implement sortDescendants to provide the order in which you would like the descendants to be traversed.

See also:

• FocusNode, for a description of the focus system.
• FocusTraversalGroup, a widget that groups together and imposes a traversal policy on the Focus nodes below it in the widget hierarchy.
• FocusNode, which is affected by the traversal policy.
• WidgetOrderTraversalPolicy, a policy that relies on the widget creation order to describe the order of traversal.
• ReadingOrderTraversalPolicy, a policy that describes the order as the natural "reading order" for the current Directionality.
• OrderedTraversalPolicy, a policy that describes the order explicitly using FocusTraversalOrder widgets.
• DirectionalFocusTraversalPolicyMixin a mixin class that implements focus traversal in a direction.